EVERETT — A Marysville man pleaded not guilty Friday to allegations that he spent much of a June night driving around Snohomish County, firing handguns at cars, houses filled with sleeping people and a group of teenage girls walking along a road in Lake Stevens.

Molly Conley, 15, of Seattle, was fatally shot in what Snohomish County prosecutors believe was the start of a violent spree they allege has been linked by forensic evidence to Erick N. Walker.

On Thursday, they charged Walker, 27, with first-degree murder in the girl’s June 1 death. He also faces four counts of drive-by shooting for bullets fired into homes in Marysville and Lake Stevens before daybreak June 2.

Walker, a Boeing employee with no criminal history, was arraigned on the charges during a brief hearing Friday in Snohomish County Superior Court.

Appearing via video link to the county jail, he pleaded not guilty to all the charges.

The defendant “exhibited extreme indifference to human life” when he shot from a passing car at Molly and her girlfriends as they walked along a road, Snohomish County deputy prosecutor Ed Stemler said in court papers.

Molly was struck in the neck. She died at the scene. The bullet that hit her has not been found.

Investigators believe her killing is connected to other drive-by shootings in Lake Stevens and Marysville in the hours afterward. Tests on five bullets recovered from those shootings have been matched to two .30-caliber handguns that were seized from Walker’s house, according to court papers.

Walker denied involvement when he was arrested June 28, although he acknowledged driving in Lake Stevens the night Molly was shot. One of the homes hit by gunfire is just blocks from his house, documents show.

Walker became a suspect in Molly’s killing after detectives determined he owned the same type of weapon forensic tests suggested was used in the drive-bys. Damage on his black Pontiac G6 coupe also reportedly was consistent it with having struck a car at one of the shooting scenes.

The investigation continues. Detectives obtained search warrants for cellphone data that they hope to use to track Walker’s movements the night of the shootings.

Walker is represented by Mark Mestel, a longtime defense attorney from Everett. In court Friday he asked Stemler for access to police reports and other investigative materials.

Stemler said the case file already is more than 2,000 pages. He made arrangements to provide it to Mestel.

The defense attorney reserved argument Friday about the $5 million bail set shortly after Walker’s arrest. He told Judge Janice Ellis he wants to examine the case file first.

She scheduled trial for Sept. 13.

Molly was a freshman at Seattle’s Bishop Blanchet High School and nicknamed “4.0” because of her good grades. Her family and friends attended Friday’s hearing, some wearing stickers bearing her name. They declined to speak with reporters.

Scott North: 425-339-3431, north@heraldnet.com.